Is the following sentence linguistically acceptable?
All the armies of Europe marched over these fields.

acceptable

Is the following sentence linguistically acceptable?
A friend of mine and a girl who was from his home town met in Vienna who was working in Europe.

unacceptable

Is the following sentence linguistically acceptable?
Who bought that piano for his secret fiancée?

acceptable

Is the following sentence linguistically acceptable?
Here's a knife which for you to cut up the onions with.


unacceptable